s390/mm: provide simple ARCH_HAS_DEBUG_VIRTUAL support

Provide a very simple ARCH_HAS_DEBUG_VIRTUAL implementation.
For now errors are only reported for the following cases:

- Trying to translate a vmalloc or module address to a physical address

- Translating a supposed to be ZONE_DMA virtual address into a physical
  address, and the resulting physical address is larger than two GiB

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index ded9548d11d9..9381879f7ecf 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -181,9 +181,35 @@ int arch_make_page_accessible(struct page *page);
 #define __PAGE_OFFSET		0x0UL
 #define PAGE_OFFSET		0x0UL
 
-#define __pa(x)			((unsigned long)(x))
+#define __pa_nodebug(x)		((unsigned long)(x))
+
+#ifdef __DECOMPRESSOR
+
+#define __pa(x)			__pa_nodebug(x)
+#define __pa32(x)		__pa(x)
 #define __va(x)			((void *)(unsigned long)(x))
 
+#else /* __DECOMPRESSOR */
+
+#ifdef CONFIG_DEBUG_VIRTUAL
+
+unsigned long __phys_addr(unsigned long x, bool is_31bit);
+
+#else /* CONFIG_DEBUG_VIRTUAL */
+
+static inline unsigned long __phys_addr(unsigned long x, bool is_31bit)
+{
+	return __pa_nodebug(x);
+}
+
+#endif /* CONFIG_DEBUG_VIRTUAL */
+
+#define __pa(x)			__phys_addr((unsigned long)(x), false)
+#define __pa32(x)		__phys_addr((unsigned long)(x), true)
+#define __va(x)			((void *)(unsigned long)(x))
+
+#endif /* __DECOMPRESSOR */
+
 #define phys_to_pfn(phys)	((phys) >> PAGE_SHIFT)
 #define pfn_to_phys(pfn)	((pfn) << PAGE_SHIFT)
 
@@ -205,7 +231,7 @@ static inline unsigned long virt_to_pfn(const void *kaddr)
 #define virt_to_page(kaddr)	pfn_to_page(virt_to_pfn(kaddr))
 #define page_to_virt(page)	pfn_to_virt(page_to_pfn(page))
 
-#define virt_addr_valid(kaddr)	pfn_valid(virt_to_pfn(kaddr))
+#define virt_addr_valid(kaddr)	pfn_valid(phys_to_pfn(__pa_nodebug(kaddr)))
 
 #define VM_DATA_DEFAULT_FLAGS	VM_DATA_FLAGS_NON_EXEC